Today, it is not uncommon for people to carry their mobile phones with them at all times. Most of these mobile phones have the capability to capture photographs or video, dramatically increasing the number of images that are captured. There is some legal basis for the expectation that subjects in captured images should control the use of their respective likenesses in those images, including what is known as the “right of publicity.” However, with the proliferation of social networking, and its associated posting and sharing of images, and the increasing ease with which those images can be captured using mobile phones and other capture devices, such rights are quickly being eroded.
One of the biggest limitations to enforcing these and other similar rights is surreptitious photographing in which the subject does not realize that his or her photograph has been taken. Although a subject may be able to hear the click of a physical camera shutter when a photograph is taken, this sound is easily obscured or drowned out by other noises, and digital cameras may not click at all as there is no physical shutter. Efforts to legislate a requirement that all cameras emit an audible sound when an image is captured have so far been unsuccessful. Moreover, even if digital cameras were required by law to emit an audio notification, such a notification has a limited range, can easily be suppressed by other noise sources, has a limited temporal window during which it is effective, and is reliant on the listening capability of the subject. Accordingly, techniques are needed that provide subjects with more effective control over the use of their likenesses in captured images.